After using the animation feature for a while I can say it's really great! A neat tool that has just the right focus. It let's you animate effectively and is not cluttered.

I found some bugs and have some wishes. Some of it is probably already on your todo-list so I thought I do a post here before doing proper bug reports/wishes.

Wishes first as they are more fun :
It would be great if the timeline started playing from your current position rather than from frame 1. With longer animations it becomes tedious to always have to look through your whole animation when doing a quick check on some motion at the end of your scene.

Scale keyframes. As you have space-drag to change the scale of the timeline but instead scale the selected keyframes (See Blender dope sheet for reference).

Colour code keyframes. For keeping track of your keys and breakdowns.

Import image sequences as animation layers. (Rotoscoping is one example of the usability of this)

A small marker in timeline at the last frame of your scene.

Floating dockers on top of Canvas only mode. To quickly bring up the layers or timeline docker without having to go back to full UI would be very useful. With shortcuts of course. (Not animation specific)


Bugs:
When pausing the timeline jumps back to the frame you started from. But if you have a longer timeline so you have horizontally scolled to your frame then when pausing the timeline scrolls to the first portion and stops at some frame within this range.

You can't paste into a frame. In non animation this is not a huge issue as you can "Merge with layer below" but with animation layers you lose all frames if you merge.

Animation layers with Transform masks doesn't display properly. Sometimes on half of the layer is displayed, etc.

It happened quite often that Krita couldn't save my document. If I changed frame it became possible again. One thing I noticed was that there was a lot of "Updating" going on in the info bar.

Would it be too much trouble to make an app to be able to download Krita drawings into Synfig?
Ken